​​The first firewalls only performed port and access controls. However, within time, these firewalls lost their reliability due to the intervention attacks in TCP communication. Then, session security was provided with status controlled firewalls (stateful firewall). However, with the evolving needs, security at gateway level for antivirus, antispam, URL filtering and IPS over firewall had needed. Systems running these services over firewalls are called Unified Threat Management. BBS positions Linux, Fortinet, Juniper, Checkpoint, Microsoft and Cisco brands in its network gateway solutions.